Combustion apparatus



July 9, 1957 J. w MlLLER QEVTALI'J 2,793,541

COMBUSTION APPARATUS Filed Dec. 15. 1952 I 4 Sheets-Sheet 2 s z .r mam 1 m m m 1. M 2 v i y 9 .A'w. MILLER ETAL 2,798,541

COMBUSTION APPARATUS Filed Dec.

4 Sheets-Sheet 3 July 9, 7 J. W. MILLER HAL 7 5 COMBUSTION APPARATUS 4 Sheets-Sheet 4 Filed Dec. 15. 1952 A INVENTORJT a///v m 41/415,?

FEEDzELQ/CK srazvy BY A Unite Ytates COIWBUSTEQN APPARATUS Application December 15, 1952, Serial No. 326,681

12 Claims. (Cl. 158-491) This invention relates to combustion apparatus and more particularly to heaters employing vaporizing pot type burners as a source of heat.

The invention here is an improvement over the construction shown in the Miller et al. U. S. Patent No. 2,374,693 and has for its object the provision of a burner the construction of which during the so-called high-fire stages of operation results in a marked improvement in performance, particularly in the reduction of the smoke content in the products of combustion.

In the drawings:

Fig. 1 is a vertical sectional view of a heater embodying the present invention.

Fig. 2 is a fragmentary horizontal sectional view of the heater shown in Fig. 1.

Fig. 3 is a perspective view of the antiexplosion baffle used in the burner.

Figs. 4, and 6 are sectional views taken along the lines 4-4; 5-5 and 6-6 respectively, in Fig. 2.

Figs. 7 and 8 are views generally similar to Fig. 4 and showing two modifications of the burner side wall construction.

Figs. 9, 10 and 11 are views generally similar to Figs. 4, 5 and 6, respectively, showing a modified construction of the top wall of the burner.

Figs. 12 and 13 are views similar to Fig. 9 and showing two modifications of the burner side wall construction.

Fig. 14 is a fragmentary view, partly in horizontal section and partly in plan, of a burner embodying a modified form of anti-explosion baflle.

Fig. 15 is a sectional view along the lines 1515 in Fig. 14.

For the purpose of illustration the invention is shown as embodied in a space heater. The heater includes an outer casing 10 and an inner casing 12 which defines a combustion chamber 14. The space between the casings 1t and 12 comprises a heat chamber 16. Within the lower end of casing 12 there is arranged a burner 18 which is supported at its lower end on brackets 20. Burner 18 is of the vaporizing pot type having a bottom wall 22, a side wall 24, and a top wall 26.

Top wall 26 is frustoconically shaped and is provided with a central opening 28 at the upper end thereof. The side wall 24 of the burner is provided with several annular series of primary air inlet openings 30. At one side adjacent its lower end, side wall 24 is provided with an indentation 32 on which an inclined partition wall 34 having a central opening 36 is supported. Adjacent its upper end the side wall 24 is provided with an annular, inwardly extending head 38 and above bead 38 the side wall is provided with an annular, outwardly extending head 40. The outer diameter of the side wall 24 at bead 40 corresponds to the inner diameter of the cylindrical casing 12 so that the head 40 seals with casing 12. Top wall 26 is seated on bead 38. Between bead 40 and head 38 the side wall 24 of the burner is provided with two vertically spaced, annular series of secondary air inlet openings 42 and 44, respectively. In the arrangeatent 2,798,541 Patented July 9, 1957 ment illustrated in Figs. 1 through 5 the lower series of openings 42 are formed in a flat portion of the wall 24 so that their axes intersect wall 26. The openings 44 in the upper series are formed in a curved portion of the head 40 so that their axes do not intersect wall 26 but extend in a direction generally parallel to or away from the plane of wall 26.

An anti-explosion baflle, generally referenced 46, is supported upon top wall 26 of the burner. Baflie 46 is shown in perspective in Fig. 3 and at various circumferentially spaced sections in Figs. 4, 5 and 6. It includes an annular rim 48 in the form of a vertical flange having a horizontal, radially inwardly extending flange 50 at its upper end. Around its inner edge flange 50 is fashioned into an upwardly extending, annular wall 52 which is bent inwardly at its upper end to provide a top wall 54 for the bafiie. At a plurality of points around the periphery of baffle 46, the side wall 52 is pressed outwardly as at 56 so that at these points the outer diameter of the baflie plate 46 corresponds with the inner diameter of the side wall 24 of the burner at the upper end thereof.

At regularly circumferentially spaced areas, the top wall 54 of baflle 46 is provided with U-shaped notches 58 which define walls 60 turned downwardly along a circumferential bend line 62. A second series of notches 64 spaced radially inwardly of the bend line 62 are also provided, the material sheared thereby being turned downwardly along radial bend lines 66 to provide walls or lugs 68 which, when the bafile 46 is arranged within the upper end of the burner, engage the top wall 26 of the burner. The lower edges of the walls 60 are also fashioned to seat upon top wall 26. Thus, the walls 68 and the walls 60 cooperate to divide the baffle plate 46 circumferentially into a plurality of circumferentially spaced channel sections 70 which extend radially inwardly from the side wall 54 and a plurality of louvered sections defined by the walls 60 between each channel section 70. Anti-explosion baflie 46 is positioned on the top wall 26 of the burner so that the lower edge of the peripheral rim 48 terminates along a line just below the secondary air inlet openings 44 and just above the secondary inlet openings 42. At circumferentially spaced points the upper edge of wall 24 is bent inwardly over the wall portions 56 of baflle plate 46 to hold the baffle plate in position on the top wall of the burner.

In general, the operation of the burner described herein is similar to that described in Valjean U. S. Patent No. 2,186,156, the only diflerence being primarily in the socalled high-fire stages of operation, i. e.,. when some or all of the air utilized forcombustion is supplied by the secondary air inlet openings 42 and 44. It is during this stage of high-fire operation that the bafiie arrangement herein described in combination with the other features of the burner provides the improved performance of the burner. During the high-fire stage of operation, secondary air for combustion is admitted through the openings 42 and 44. Air entering through openings 44 is deflected by the annular wall 52 so that it rises through an annular zone adjacent the wall of the casing 12. The air entering the burner through the openings 42, it will be observed, is divided into two portions, that portion entering openings 42 adjacent the outer ends of channels 70 and that portion which enters the openings 42 adjacent the outer ends of the louvered sections defined by the walls 66. The air entering the louvered portions is deilected upwardly by the walls 60 into an annular zone spaced concentrically inwardly of the zone formed by the air entering the openings 44. The air entering the outer ends of channels 70 is deflected upwardly by the top wall 26 of the burner through the open inner end of the channels 79 into an annular zone spaced concen-.

tnically inwardly of the zone formed by the air flowing upwardly through the louvered sections of the burner. The'p'rimar'y air'f'or combustion is, bf course, supplied through the openings 30 which combines with the vapors from the fuel admitted to the base of the burner through the pipe line 72 and passes upwardly, through the central opening 28 in the top wall 26 of the burner.

As explained in the above mentioned Miller Patent No. 2,374,693, the positive direction of the air upwardly through the combustion chamber and the concentric annular zones provides improved combustion and a most efiicient transfer of heat to the heat chamber 16. The arrangement also reduces the velocity of air through the combustion apparatus so as to produce, even under high fire, a lazy, quiet flame. It has been determined that, by forming the walls 60 around baflle plate '46, the performance of the burner is improved even over that shown in said Miller patent. The reason for these improved results probably lies in an improved mixing of the secondary air intothe gases rising from the opening 28 at the upper end of the burner. It has been definitely established that the burner arrangement described herein produces a much cleaner fire, the presence of smoke in the products of combustion being substantially reduced at all ranges of drafts under high-fire operation.

In Figs. 7 and 8 there are shown modifications of the side wall construction of the burner adjacent the s'econd-' ary air inlet openings 42 and 44. It has been determined that the performance of the burner is also somewhat improved by forming the lower row of secondary inlet openings 42 such that the axes of these openings do not intersect the top wall 26. Thus, as shown in Fig. 7, the shape of the side wall 24 adjacent the head 40 is altered so that both the openings 42 and 44 are formed in a continuously curved portion of the wall, the axes of openings 42 extending generally parallel to the plane of the wall '26. As a means for simplifying the formation of these holes, the portion of wall 24 between the bead 38 and the bead 40 may be formed as a flat outwardly flared wall portion so that the holes 42 and 44 may be punched normal to the flat surface as indicated at 74. In the arrangements shown in Figs. 7 and 8 the air entering the burner through openings 42 does not impinge against the top wall 26 but does strike the inclined louver wall 60 and is deflected upwardly thereby. In the arrangement illustrated in Fig. 7 the air entering the openings 44 impinges against the upper portion of the annular wall 52, and in the arrangement illustrated in Fig. 8 the air entering the openings 44 impinges against the annular rim 48 of the baffle plate.

In the arrangement illustrated in Figs. 1 through 8 it will be observed that the edge portion of the top wall 26 which defines the opening 28 is aligned generally in the same horizontal plane as the inner upper peripheral edge of the radially arranged channels 70. It has been found that the performance is improved to an even greater extent if the top wall 26 of the burner is extended upwardly above the plane of the uppermost edges of baffle plate 46. Thus, as shown in Figs. 9, 10 and 11, which correspond generally with the sectional views illustrated in Figs. 4, and 6, the top wall 26 of the burner is provided with a neck portion 76 which terminates in a plane spaced vertically above the plane of the edges of baflle plate 46. The provision of a high neck such as illus-. trated at 76 appears to promote a more thorough mixing of the secondary air with the gases rising through opening 28' without the production of excessive turbulence in' the combustion chamber 14.

In Figs. 12 and 13 there is shown the improved baffle 46 in connection with a burner having a top wall 26 provided with the high neck flange 76 and with a side wall 'cpnstruction such as shown in Figs. 7 and 8. The greatest improvement in the performance of the burner herein described has been obtained by the constructions shown in Figs. 12' and 13. In each-of these arrangements it will be observed that some of the air entering the sec- 'th'ro'ughchannels 70 and is directed upwardly into an annular zone by the high neck 76. The air entering others of the openings 42 flows upwardly over wall 26, strikes the louver wall 60 and is directed upwardly into another annular zone concentric with the previously mentioned annular zone. The air entering the openings 44 is deflected upwardly by the outer peripheral wall of the baflle plate into a third annular zone concentric and spaced outwardly from the first two mentioned annular zones.

It will be observed that in the construction shown in the previous embodiments illustrated the louver wall 60 is formed by the metal sheared and bent downwardly from the notch 58. Thus, the side walls for the channels 70 are defined by the walls or lugs 68 adjacent the radially inner ends of the channels.

If it is desired to provide side walls for the radial channels 70 of the baflle plate 46 of greater radial extent, the construction shown in Figs. 14 and 15 may be adopted. In this arrangement it will be observed that the louver wall 78 is fashioned from a separate stamping 79 which. also provides a top wall portion 80. The stamping 79 is fashioned with tabs 82 which are turned under the inner edge of the top wall 54 of the baflle. In this arrangement the notched out portion 84 which forms the louvered section of the bafile may be utilized to the extent desired for providing side walls 86 for the channels 70. The side walls 86, it will be observed, are of greater radial extent than the walls 68 in the baffle construction described previously.

We claim:

l. A baifle plate for use with a vaporizing pot type burner having a centrally apertured top wall comprising an annular member having a top wall portion and a continuous, generally imperforate annular wall portion depending from the outer peripheral edge thereof, said top wall portion being centrally apertured and being inclined upwardly in a radial inward direction, a plurality of circumferentially spaced, radially disposed walls depending from said top wall portion, said radially disposed walls cooperating with said top wall portion to divide the baffle plate circumferentially into a plurality of circumferentially spaced, radially extending channels, said top wall portion having circumferentially spaced portions removed therefrom so that the sections between successive channels are substantially open at the top and the channels adjacent thereto are closed at the top. by said top wall portion of said baflle plate, said sections which are open at the top each having an upwardly inclined wall extending across said section ina radially inward direction whereby a portion of the air admitted beneath the lower edge of said annular wall portion of said baffle. plate is directed upwardly and generally radially inwardly through said closed top channels and upwardly through said central aperture in said top wall portion, and another portion of the air admitted beneath the lower edge of said annular wall portion is directed upwardly by said inclined walls into an annular zone spaced concentrically outwardly of the air discharged from said closed top channels, said radially disposed walls and said inclined walls having their lower edges terminating in a conical plane inclined similarly to the inclination of said top wall portion.

2. The baffle plate set forth in claim 1 wherein the upper edges of said inclined walls are spaced radially outwardly of the inner edge of said top wall portion and wherein the lower edges of said inclined walls are spaced radially inwardly of the lower edge of said annular wall portion.

3. The baffle plate set forth in claim 1.wherein said radially disposed walls are connected along their upper edges with said top wall portion along radially extending bend lines.

4. The batfle plate set forth in claim 1 wherein said top wall portion has an annular, inner peripheral portion extending across said opened top sections, said inclined walls being integrally connected at their upper ends with the outer circumferential edge of said inner peripheral portion by a generally circumferentially extending bend line.

5. The bafile plate set forth in claim 1 wherein said inclined walls are formed as separate members and secured at their upper ends to said top wall portion of said baffle plate.

6. In combination, means forming a combustion chamber having a side wall, a pot type burner having a side wall, said burner being located below said combustion chamber within the first mentioned side wall, means forming a sealed connection between the side wall of the burner and the side wall of said combustion chamber, said burner being provided with a top wall having a central opening to permit gases to flow outwardly out of said burner into said combustion chamber, a centrally apertured baflle plate positioned on said top wall and having an annular, generally upright wall spaced radially inwardly from the side wall of said combustion chamber, the side wall of the burner being provided with a series of apertures spaced circumferentially therearound in a plane below said battle plate and above the top wall of the burner, means on said baflle plate forming a plurality of closed top channels extending radially inwardly toward said central aperture, said channels being spaced apart circumferentially of said baflle plate, means on said baffle plate forming inclined walls extending upwardly from said top wall of the burner, said last mentioned means extending circumferentially across the space defined between adjacent channels whereby the air entering through some of said apertures in said series is directed radially inwardly through said channels and the air entering others of said apertures in said series impinges against said means forming said inclined walls and is directed upwardly.

7. The combination set forth in claim 6 wherein said top wall of said burner inclines upwardly in a radially inward direction and wherein the inner ends of said channels terminate along a line spaced radially inwardly of the upper edges of said inclined walls of said baffle plate.

8. The combination set forth in claim 6 wherein said top wall of said burner inclines upwardly in a radially inward direction, said inner ends of said channels terminating along a line spaced radially inwardly of the upper edges of said inclined walls of said bafile plate and said apertures in said burner side wall having their axes extending in a plane generally parallel to the plane of said top wall.

9. The combination set forth in claim 6 wherein said top wall of said burner has a neck portion defining said central aperture in said top wall of said burner, said neck portion extending upwardly above the uppermost edges of said battle plate.

10. The combination called for in claim 6 wherein the side wall of the burner is provided with a second series of apertures spaced circumferentially therearound in a plane above said first mentioned series of apertures and intermediate the upper and lower edges of said annular, generally upright wall whereby air entering said last mentioned series of apertures is directed upwardly by said generally upright wall in a zone spaced radially outwardly of the streams of air flowing from said first mentioned series of apertures.

11. The combination set forth in claim 10 wherein said top wall of said burner is provided with an annular wall defining said central opening, said. last mentioned annular wall extending upwardly beyond the line of intersection between the plane of the top walls of said channels and said last mentioned annular wall.

12. The combination set forth in claim 10 wherein the axes of said lower series of apertures are disposed relative to the top wall of the burner to direct air flowing therethrough in a direction away from said top wall.

References Cited in the file of this patent UNITED STATES PATENTS 2,181,407 Miller Nov. 28, 1939 2,258,679 Hayter Oct. 14, 1941 2,374,693 Miller et a1. May 1, 1945 2,581,238 Cauley Jan. 1, 1952 

